upgrade quant mode

README.md

@@ -4,7 +4,7 @@
 
 ## 安装
 
-通过pip（推荐）：
+通过 pip（推荐）：
 
 ```
 pip install imgyaso
@@ -16,7 +16,7 @@ pip install imgyaso
 pip install git+https://github.com/apachecn/imgyaso
 ```
 
-并且安装 [ImageMagick](https://imagemagick.org/script/download.php) 和 [pngquant](https://pngquant.org/)。
+并且安装 [ImageMagick](https://imagemagick.org/script/download.php)。
 
 ## 使用说明
 
@@ -28,7 +28,7 @@ imgyaso [-h] [-v] [-c COLORS] [-m {grid,noise,trunc,quant,thres}]
 -c COLORS: 颜色数，只对 trunc, quant 模式有效
 -m MODE: 模式名称，值为 grid（灰度网格仿色），noise（灰度扩散仿色），
          trunc（灰度截断），quant（颜色缩减），thres（自适应二值化），
-         默认为 grid
+         默认为 quant
 -o OFNAME: 输出文件名称，默认和输入文件相同
 fname: 输入文件名称
 ```

imgyaso/__main__.py

@@ -8,7 +8,7 @@ from .quant import pngquant_bts
 from .trunc import trunc_bts
 from .util import *
 
-modes = ['grid', 'noise', 'trunc', 'quant', 'thres']
+modes = ['quant', 'grid', 'noise', 'trunc', 'thres']
 
 is_img = lambda s: re.search(r'\.(jpg|jpeg|gif|png|bmp|webp|tiff)$', s)
 

imgyaso/quant.py

-import subprocess as subp
-import tempfile
-import uuid
-import os
-from os import path
 import sys
+import cv2
+import libimagequant as liq
+from PIL import Image
+from io import BytesIO
 from .util import *
 
 def pngquant(img, ncolors=8):
@@ -13,22 +12,31 @@ def pngquant(img, ncolors=8):
 
 def pngquant_bts(img, ncolors=8):
     img = conv2png(img)
-    fname = path.join(
-        tempfile.gettempdir(), 
-        uuid.uuid4().hex + '.png'
-    )
-    with open(fname, 'wb') as f:
-        f.write(img)
-    subp.Popen(
-        ['pngquant', str(ncolors), fname, '-o', fname, '-f'],
-        stdout=subp.PIPE,
-        stderr=subp.PIPE,
-    ).communicate()
-    with open(fname, 'rb') as f:
-        img = f.read()
-    os.unlink(fname)
-    return img
+    img = Image.open(BytesIO(img)).convert('RGBA')
+    w, h = img.width, img.height
+    bytes = img.tobytes()
+    
+    attr = liq.Attr()
+    attr.max_colors = ncolors
+    img = attr.create_rgba(bytes, w, h, 0)
+    res = img.quantize(attr)
+    res.dithering_level = 1.0
+    bytes = res.remap_image(img)
+    palette = res.get_palette()
     
+    img = Image.frombytes('P', (w, h), bytes)
+    
+    palette_data = []
+    for color in palette:
+        palette_data.append(color.r)
+        palette_data.append(color.g)
+        palette_data.append(color.b)
+    img.putpalette(palette_data)
+    
+    bio = BytesIO()
+    img.save(bio, 'PNG', optimize=True)
+    return bio.getvalue()
+
 def main():
     fname = sys.argv[1]
     img = open(fname, 'rb').read()

requirements.txt

 numpy
 scipy
 opencv-python
+pillow
+libimagequant
\ No newline at end of file